There is a known conference system that uses a multi-point control unit (MCU) to perform a teleconference. There is a case that, in such conference system, switching the MCU controlling a specific conference room to another MCU while maintaining the conference room. In another known conference system, for example, when available resources in a first MCU are not enough, address information on a second MCU having excessive resources is transmitted to a plurality of conference terminals participating in a conference room controlled by the first MCU. Each of the conference terminals receives the address information and switches a connection destination from the first MCU to the second MCU based on the address information. The control of the conference room is taken over by the second MCU, and thereby, the conference room continues.